Advances in modern technology, network connectivity, processing power, convenience, and the like, support an ever increasing number of interconnected devices such as mobile devices, cell phones, tablets, smart-cars, wearable devices, etc. In turn, these advances present new challenges and create new opportunities for network operators and third party service providers to efficiently target, communicate, or otherwise exchange signals between networked devices. Indeed, modern approaches for wireless signal transmission must often account for complex conditions and dynamic factors such as network traffic, signal propagation through various media, spectrum/frequency constraints for signal transmission, and the like.
One approach that attempts to address some of these challenges includes beamforming, and more specifically, time reversal beamforming. Beamforming generally refers to a signal processing technique used in sensor arrays for directional signal transmission or reception, and time reversal beamforming particularly exploits reciprocity (or time-invariance) for electromagnetic propagation channels that are not “polluted” by non-time-invariant components (such as EM nonlinearities and DC magnetic field generators). With respect to operations for time reversal beamforming, a receiver device temporarily transmits signals that are received by a transmitter device (e.g., beamforming device). The transmitter or beamforming device measures and records amplitudes at its radiating elements, and further applies amplitude and phase modulations to a transmission signal to produce a phase-conjugate signal of the prior measured and recorded field amplitudes. While conventional devices, such as Active/Passive Electronically Steerable Array (AESA/PESA), typically include modular structures which make amplitude measurements simple, metamaterial components often do not allow direct access to radiating elements and/or do not support direct amplitude measurements. In fact, in many instances involving metamaterial components, there are no well-defined radiating elements (e.g., as in a tightly-coupled array of scattering elements coupled to a leaky waveguide). Accordingly, many challenges arise when employing metamaterial components for beamforming signals.